The field of the invention pertains to means to override and control the interior or exterior lights of a structure in response to an alarm or other signal and, in particular, to compact electrical control means for indoor or outdoor lights actuatable in response to an alarm signal or other low voltage signal from an auxiliary device.
U.S. Pat. No. 4,276,542 discloses an indoor operated switch to optionally insert an audible alarm and light flashing circuit in an exterior light circuit and to thereby give notice on the outside of the home of an emergency condition inside the home. The device requires the use of a three position wall switch which turns the external light on or off in a conventional manner but provides a third or alert position which engages the flashing circuit and audible alarm circuit. The device is not actuated by an external alarm sensor or other automatic low voltage device but rather relies upon the three position switch being manually placed in the alert position to engage the flashing circuit and audible alarm circuit.
U.S. Pat. No. 4,287,509 discloses a strobe lamp triggering circuit which senses the input to an audible signalling component of a fire alarm system. The circuitry includes an optical isolation element and an emergency alternating current power supply for the strobe lamp triggering circuit. The audible signalling component sensing circuit, however, is driven by the low voltage audible fire alarm system.
U.S. Pat. No. 3,916,404 discloses circuitry activated by any one of a number of heat sensing devices so as to cause a recognizable sound and visual means to indicate the location of the exit from the structure. The circuitry requires completely separate wiring to the various lamps which operate at a low voltage from a transformer and rectified alternating current power supply or, in the event of failure of the alternating current power supply, an integral low voltage battery.
U.S. Pat. No. 4,148,023 similarly discloses an alternating current powered emergency exit indicator to signal with a high intensity light and audible alarm the location of an emergency exit. This particular circuit, however, provides for the activation of the additional high intensity light in case of emergency, in particular, a smoke emergency sensed by a detector in the circuitry. Thus, the emergency exit lights can be kept at a relatively low level sufficient to indicate the emergency exit without causing any distraction to an audience in a movie theater or night club, nevertheless providing an extremely bright smoke piercing light in the event of an emergency.
U.S. Pat. No. 4,101,880 discloses an audio-visual signalling device utilizing an inductance and an interrupter in series with the inductance. With periodic interruption of the interrupter, the inductance magnetic field periodically decays actuating a flash tube to cause a flashing signal in addition to the auditory signal.
The patents above disclose extensive low voltage circuitry or special circuitry and lighting along with auditory signalling means. Such devices are expensive to install and to service. The device in U.S. Pat. No. 4,276,542, which relies on the existing two wire power circuit to the light, requires manual operation of the alert signal to flash the light. None of the disclosed art above suggests simple, inexpensive and compact circuitry that automatically overrides an internal or external light circuit in response to an alarm signal to thereby flash the light regardless of whether the light is on or off prior to the alarm signal.